LTC3542IDC#TRPBF

The LTC3542 is a high efficiency monolithic synchronous buck converter using a constant frequency, current mode architecture. Supply current during operation is only 26μA, dropping to <1μA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3542 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. The output voltage is adjustable from 0.6V to VIN. Internal power switches are optimized to provide high efficiency and eliminate the need for an external Schottky diode. Switching frequency is internally set at 2.25MHz, allowing the use of small surface mount inductors and capacitors, and it can synchronize to an external clock signal with a frequency range of 1MHz to 3MHz through the MODE/ SYNC pin. The LTC3542 is specifically designed to work well with ceramic output capacitors, achieving very low output voltage ripple and a small PCB footprint.

Applications

• Cellular Telephones
• Wireless and DSL Modems
• Digital Cameras
• MP3 Players
• PDAs and Other Handheld Devices

Key features

• High Efficiency: Up to 96%
• High Peak Switch Current: 1000mA
• Low Output Ripple (<20mVPP Typical)
• Burst Mode Operation: Only 26μA
• Very Low Quiescent Current: Only 26μA
• 2.5V to 5.5V Input Voltage Range
• 2.25MHz Constant Frequency Operation
• 1MHz to 3MHz External Frequency Synchronization
• Low Dropout Operation: 100% Duty Cycle
• No Schottky Diode Required
• Internal Soft-Start Limits Inrush Current
• 0.6V Reference Allows Low Output Voltages
• Shutdown Mode Draws <1μA Supply Current
• ±2% Output Voltage Accuracy
• Current Mode Operation for Excellent Line and Load Transient Response
• Overtemperature Protected
• Available in 6-Lead 2mm × 2mm DFN and Small TSOT